Shock absorber



Dec. 2s, 1924.. ,n 1526,34?

' J. H OFMAN N Si-IOCK ABSORBER Dec, 23, 1924.

.1. HCI-'MANN SHOCK ABSVORBER Filed Sept. 13, 1920 3 Sheets-Sheet 2 Patented en. 235, 1924-.

Unire STATES PATENT JOSEF HOFMANN, OF BAUIVIAROCHE, SWITZERLAND, SSvIG-NOR TO ALFRED JOEL S5 CO., OF ZURICH, SWITZERLAND.

SHOCK ABSORBER.

Application led September 13, 1920. Serial No. 409,939.

To all whom t may concern.'

Be it known that l, Josnr HOFMANN, ot' Baumaroche, Switzerland, a citizen of Poland, have invented certain new and useful Improvements in Shock Absorbers; and I do hereby declare the following to be a full, clear, and exact description ot' the invention, such as will enable others skilled in the art t-o which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specilication.

My invention relates to shock absorbers for vehicles, to be included between a inember of the running gear and a member of the frame of a. vehicle.

It comprises two levers pivotedtogether intermediate their ends, one ot which levers is, in eiect, a bell-crank lever, and the other is substantially straight. lincluded between Ione end of the substantially straight lever and the end of one arm of the bell-crank lever is the cushioning device, comprising either a coil spring or springs and an air cushion.

rlhe cushioning device arranged between 'a straight lever and a bell-crank lever appears to have superior shock absorbing properties for small amplitude of movement, because when compressedto the point when the main spring becomes active, said spring then stretching will de-compress the cushioning device, and permit a greater total amplitude of movement of the combined suspension. Besides this advantage it gives a compact arrangement that is readily placed on the vehicle and is not unsightly, while all parts are easily accessible.

Referring to the drawings, in which like parts are similarly designated- Figure 1 is an elevation, partly in section, of one form of my invention, utilizing coil springs.

Fig. 2 isz a like View, utilizing an air cushion.

Fig. 3 illustrates a modiiication of Fig. 1, employing a single coil spring.

Fig. 4 shows a modilied arrangement illustrating a depending type. p

ln the drawings, 1 represents the rear axle tube, 2 the bra-ke drum thereon, and 3 ed end of a tube or cylinder 15.

a bracket seccured to the interior ot' the brake drum and curved to project over the drum, while the body spring is indicated at 1, with a pivot 22 at its eye.

Pivoted at one end at 5 in the bracket 8 is a substantially straight lever 6, to whose opposite end is pivoted at 7 the end of a plunger rod 8.

Pivoted between the ends of lever 6 at 9 is a bell-crank lever comprising an arm 10 pivoted in the end of the spring l and a plate 11 extending from said arm 10 and constituting the second arm of the bellcrank lever. The pivot 9 is substantially at the point where the two arms of the bellcrank join one another.

On the plate 11 seats one end of a coil spring 12 whose other end rests on a threaded ring 13 having spanner holes le whereby this ring may be adjusted along the thread- The cylinder 15 has an inwardly directed flange 16 through the central opening of which projects the rod 8. Below the flange 16 on the plate 11 is a buller ring 11a of rubber or other material.

Resting against this flange 16 is one end of a coil spring 17, whose other end rests against a plunger or plate 18 fitting loosely within the cylinder 15. The plunger plate has a pivot connection at 19 with the end oitl plunger rod S.

The cylinder 15 has a longitudinal groove 2O in which is tree to slide a lug 21 on plate 18 that prevents the plate from rotating.

lt will thus be seen that the two springs, which are substantially of the same strength, are arranged in tandem, giving a short construction with comparatively large amplitude, and consequently a very soft action. The main spring lhas tull spring movenient, and its e-liciency is not impaired by the attachment of the shock absorber.

In the modilication F 2, the straight lever 6a is pivoted to the bracket 3 at The arm 10a of the bell-crank lever is pivoted to the body spring t at 31, and the other arm 11a has pivoted to it at 22 a plunger 23. rlhe two levers are pivoted together at 9.

The lever 6a has a spherical casing 24, onto which screws the semi-spherical cover containing an outer fabric sack 26 and an inner inflatable rubber sack 27 provided with an inflating valve 28. The cap or cover 25 screws onto the spherical portion 24 at 29. A rubber bumper is provided at 30, which, on too great a shock, may strike the spring 4. The operation of the device yas shown in Fig. 1 is as follows:

v a heavier shock occur,the main spring 4 is Vlengthens, and spring eye 22 then moves also compressed to al corresponding degree. This spring, however, when compressed,

slightly toward bracket 3 and moves spring support 11 slightly downward. This results in 'decompressing thecoil 'spring (or springs) and renders the shock absorber active again.

In the case of encountering rva hole in the Vroad'the operation will be reversed. The coil spring is decompressed until its tension l is so decreased'as to permit the main spring 4 to begin to decompress. In this case the spring eye 22 moves away from the bracket 3,V and moves spring support 11 slightly upward. This action results/in compressing the strongly. decompressed coil spring, or springs, and brings the shock absorber back into an activecondition.

In the case of the arrangement of levers as shown-inFig. 2, the operation is analogous, though the leversare arranged ina reversed Jfashion. `Whe`n pivot 5 moves upward, cylinder 24 and the enclosed air cushion :press upon plunger ,23.7 When this pressure is high enough, spring 4 is compressed, eye 31-v moves toward bracket 3 and moves plunger 23 downward, thus decompressing the air cushion. In the case-of a reversed movement olf' the axle of the car, the result isfthe saine as explained-with respect to Fig; 1. y

In Fig. 3 I have shown a single spring included between levers 6 and 10-11. In this construction the rod 8 is pivoted at 19 to a head 15"L provided with an adjusting ring-13 screwed on the exterior of the. head 15a. One end of the spring 12 rests against this head and the other end rests against the piaf@ 11.

straight lever is pivoted to the frame extension 3a. at 5. A shackle 51 acting on the second lever is pivoted at 22 to the end of the f body spring and at 5i1 to thelever 50. On the end of lever 50 is pivoted at 52 one end of a rod 53 having at its opposite end a ball 54. The rod is screwed into-.a pivot ele- Vment 55and locked by a nut 56. On the port 11 secured by rivets V64., or otherwise,I

to the shackle 51 between the pivot points 22 and 9. A hole 65 is provided in the plate 11 to allow'free movement of rod 53. Surrounding the rod 5.31 and covering` the plate 57 is a leather dust protector, and theball is covered by a cup 67 for containing grease. e

Inasmuch as plate 11 is connected to the shackle 51 between its ends, these two elements act as a bell-crank lever, the operation being such that when the elements 1 and 2 move toward one another, the plate 11 moves away from pivot 52 and compresses the springs 12 and 17.

The springs this instance also are of substantially the same strength, but by reason of the larger diameterfof spring 12 the wire from which it isfmadel must be heavier than the wire of springv 17, which is of less diameter thanspring 12.

When the elements 3 and b move away from one another the springs expand as the plate 11- moves toward the pivot 52. :Ati the same time the shackle 51 has a slight rocking movement about the point 22 where it is supported on the spring b, and the point 9. acts as a pivot for the lever 50 whose one end carries the load atv 5 andwhose other end 52 carries the counterbalancing spring tension device. The springs, which are in tandem, are included between the lever 50 and the bell-crank lever formed by plate 11 and shackle 51, and the two levers are V pivoted together at 9. Y Y

In ythese constructions the shock absorbers are short, to curbs.

I elaimy g l. A shock absorber comprising two give proper clearance oit levers one of which is a bell-,crank lever,

one arm of whichis substantially. atv right angles to the other and constitutes a seat for a cushioning device, the other lever-.being substantially straight` and pivoted be-` tween its ends tothe other armof` the bellcrank lever adjacent said-V seat, a plunger pivoted tothe end of said, lever and" compressingA saidA` devi-ee against Y saidv seat `when 'i fit) the opposite ends of said levers are moved apart.

2. A shock absorber comprising two levers pivoted together between their ends, one of which levers is substantially straight and the other a bell-crank lever, and a cushioning device comprising two concentric coil springs arranged to act in tandem, between the levers. v

8. A shock absorber comprising two levers pivoted together between their ends, one or' which levers is substantially straight and the other a bell-crank lever, a cushioning device between two adjacent ends of the levers, and a plunger and plunger rod connected to one of the levers, said plunger acting to compress the cushioning device when the said ends of the levers move relatively to` one another.

4l. A shock absorber comprising a substantially straight lever, a bell-crank lever having an arm for connection to a running gear element, and another arm constituting a spring support, said levers pivoted together between their ends, a coil spring on said support, a cylinder within the coil spring and having al ring on which said spring seats, a liange on the cylinder on which said spring rests and a plunger engaging the latter coil spring and connected to the substantially straight lever.

5. In a shock absorber, a straight lever and a bell-crank lever, one arm of said bellcrank lever constituting a spring support, a. cylinder, a ring external oi said cylinder and adjustable longitudinally thereof, a coil spring surrounding said cylinder and included between said ring and support, an inwardly directed flange in said cylinder, a plate within said cylinder a coil spring between said plate and flange, and means connecting said plate and said straight lever.

6. In a shock absorber, a cylinder having an inwardly directed flange and provided with a longitudinal groove, a plate in said cylinder having al lug free to ride in` said groove, an external ring on said cylinder, a coil spring supporting said ring and cylinder, a pair of levers pivoted together, said spring supported by one of the levers and said plate connected to the other lever.

T. A shock absorber comprising two levers pivoted together, one of which levers is substantially straight and the other a bellcrank lever, a coil spring between adjacent ends of the levers, and means pivoted to said straight lever and acting on said spring to compress it when the said adjacent ends of the levers are moved apart.

8. A shock absorber comprising two levers pivoted together between their ends, one ot which levers is substantially straight and the other a bell-crank lever, a spring supported on one arm of the bell crank lever, a plunger, a rod pivoted to said plunger and to the end of the substantially straight lever, sai-d plunger arranged to eect compression of said spring.

9. In a shock absorber, two levers pivoted together, one oi which comprises a lever having an extension at an angle thereto, and tandem springs included between said eX- tension and the other lever.

10. In a shock absorber, two levers pivoted together, one of which is a bellcrank lever, and the other a substantially straight lever, said bell crank lever arranged for the connection of one arm to a vehicle body spring, a cushioning device included between the other arm of said bell-crank lever and said straight lever to be compressed when the vehicle is subjected to shock, and said compression being partly reduced by the extension of the vehicle spring when under shock by oppositely moving said bell-crank lever.

ll. A shock absorber comprising a substantially straight arm, a bell crank lever one arm thereof pivoted between the ends of said straight arm, a spring seated on the other bell crank lever arm on the side thereof away from said straight arm, seating means for the opposite end of said spring, and means pivotally connecting said seating means to said straight arm.`

12. A shock absorber comprising a substantially straight arm, a bell crank lever, one arm thereof pivoted between the ends of said straight arm, a spring seated on the other bell crank lever arm on the side thereot away from said straight arm, seating means for the opposite end of said spring, means pivotally connecting said seating means to said straight arm and an alined extension for said one arm forming together therewith a shackle for connection to vehicle sprinef.

In testimony that I claim the foregoing as my invention, I have signed my name hereto.

JOSEF HOFMANN.

lUS 

